Mark empty implementations of drm_of_get_data_lanes_count and
drm_of_get_data_lanes_ep as static inline, just like the rest
of empty implementations of various functions in drm_of.h .
Add missing comma to drm_of_get_data_lanes_count_ep() .

Fixes: fc801750 ("drm: of: Add drm_of_get_data_lanes_count and drm_of_get_data_lanes_ep")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220612132152.91052-1-marex@denx.de